Hydraulic system for boring machines and the like



Sept. 26, 1939. w SCHMjDT 2,174,044

HYDRAULIC SYSTEM FOR BORING MAQELINES AND THE LIKE Original Filed July 23,1931 5 Sheets-Sheet 1 Jwmntoz com-m :n'sc mm Sept. 26, 1939. I i w. D. SCHMIDT 4,

HYDRAULIC SYSTEM FOR BORING MACHINES AND THE LIKE Original Filed July 23, 1931 5 Sheets-Sheet 2 600' ooq ooo 0Og gnwhto o w. D. scHMiD 2,174,044 HYDRAULIC SYSTEM FOR BORING MACHINES AND THE LIKE v Sept. 26, 1939.

Original Filed July 23, 1931 5 Sheets-Sheet 3 g I y] 4'7 55 j 1 116 g 6a Wmium ID. Schmidt Sept. 26, 1939. r w. -r 2,174,044

HYDRAULIC SYSTEM FOR BORING MACHINES AND THE LIKE I Original Filed July 25, 1951 5 Sheets-Sheet 4 William Schmidt Sep 1939. w. D. SCHMIDT HYDRAULIC SYSTEM FOR BORING MACHINES AND THE LIKE Original Filed July 23, 1931 5 Sheets-Sheet 5 gummy? o1 Wil ufirh ILSchmidT Patented Sept. 26, 1939 PATENT, OFFICE HYDRAULIC SYSTEM roe BORING A onnms AND THE LIKE William D. Schmidt, Worcester, Mass., assignor to The Heald Machine Company, Worcester, Mass, a corporation of Massachusetts Application July 23, 1931, Serial No. 552,625 Renewed July 15, 1936 29 Claims.

The present invention relates to hydraulic systems for use in automatic machines for performing boring or similar operations and is especially directed to hydraulic systems which are arranged for performing operations on successive workpieces automatically.

The principal object of the present invention is to provide a subsantially universal system for controlling the various movements of a machine in order to permitthe desired operations ofthe machine to be performed automatically. According to the present invention which is disclosed inconnection with a multiple head boring machine, a reciprocating carriage is arranged to procure a relative movement between a tool and workpiece,

the rate of movement of the carriage being automatically controlled and varied so that the carriage may be moved rapidly when the tool and work are not in operative relation and so that the carriage may be moved at a relatively slow rate while the tool and work are in operative relation. The machine also permits the operation of the tool to be controlled automatically, the said tool being actuated only during the cutting stroke on the work, and being brought to rest as soon as the cutting stroke is completed. The machine is further'constructed in such a manner that the carriage may be brought to rest in any desired position of travel as, for-example, at the completion of each boring operation. Especially in boring or turning machines in which the workpiece is carried past the tool during the boring operation and is then withdrawn from operative position, the rotating tool describes a spiral orhelix on the finished surface during the separation of the workpiece from the tool. In order to avoid the spiral cut, the tool is brought to rest automatically at the end of the 0 boring operation so that the subsequent withdrawal movement of the workpiece from the tool leaves only a single straight line along the finished surface, the straight line being much less objectional than the spiral cut on the finished surface.

' In order that the tool may be brought to rest before the withdrawal movement of the workpiece from the tool it is desirable to provide for a predetermined dwell of the carriage carrying the workpiece at the end of the carriage movement so that the tool vwill not be rotating during the withdrawal movement. This dwell inthe carriage movement is obtained by the use of a pilot valve period subsequent to the shifting of the pilot valve by the carriage movement.

During the setting up of the machine, it is desirable to reciprocate the carriage independently of the operation of the remainder of the machine elements and the present invention is arranged to permit the rotary tools to remain stationary during the reciprocation of the carriage or, if desired, to be continuously actuated regardless of the movements of thegcarriage. Other objects and advantages of the invention will appear from the following detailed description taken in connection with the accompanying drawings in which- Fig. 1 is a front elevation of a boring machine embodying the invention.

Fig. 2 is a plan view of the machine of Fig. 1.

Fig. 3 is an end elevation of the machine as seen from the left of Fig. 1.

Fig. 4 is a side elevation of the control mechanism.

Fig. 5 is a plan view partly in section of a portion of the mechanism of Fig. 4.

Fig. 6 is a fragmentary elevation of the mecha nism for controllingthe speed of the carriage.

Fig. 7 is a section along the line of Fig. 4.

Fig. 8 is a section along. the line 8-8 of Fig. 4.

Fig. 9 is a section along the line 9-9 of Fig. 4.

Fig. 10 is a section along the line Ill-l0 of Fig. 4.

Fig. 11 is a fragmentary sectional view of one of the valves for controlling the speed of the can'iage.

Fig. 12 is a diagrammatic view of the hydraulic control system. Y

Fig-13 is a diagrammatic view of the reversing lever and the mechanism for stopping the movement of the table, the parts being in inoperative position.

40 Fig. 14 is a view similar to Fig. 13 with the parts in. operative position.

Fig. 15 is a fragmentary side elevation of th upper end of the reversing lever.

Like reference characters refer to like parts throughout the drawings. Referring particularly to Fig. 1, the machine comprises a base 1 upon which is slidably mounted a table or carriage 2 on guideways 3, Fig. 3. Bridges 4 and 5 at oppflsite ends of the base span the guideways 3 for the carriage, toolheads 6 and 1 being mounted on the upper surfaces of the right and left hand bridges respec- .tively, thetools in the construction shown being which controls the main valve a predetermined rotary boring tools. As shown in Figs. 2 and 3,-

each bridge is arranged to support a plurality of toolheads, all the toolheads 6 on the right hand bridge being driven as a unit from a shaft 8, which carries a pulley 9, by a driving belt I0 which passes from said pulley 9 successively around the pulleys II on the toolhead spindles and idling pulleys l2 adjustably mounted in a horizontal slot 3 in th bridge. Similarly the spindles on the toolhe'a s I on the left hand bridge are rotated in the same manner, by a belt ID from a pulley 9' carried by a shaft 8, the belt passing around pulleys H on the toolheads and idling pulleys l2. The two shafts 8 and 8' are each actuated from the main drive shaft |4 which is rotated from a source of power such as a motor |5 by a belt or chain drive to a pulley or sprocket IS on the shaft I4, said drive shaft l4 being connected to the shafts 8 and 8 by clutch and brake units i1 and i8 respectively of usual construction. In this manner, the spindles in the toolheads on either bridge may be rotated independently of the movement of the spindles in the toolheads on the opposite bridge. Throughout the specification the toolheads on each bridge are referred to as a single toolhead, and the corresponding workpieces referred to as a single workpiece.

The clutch and brake units I1 and I8 are similar in construction and a description of one will suffice for both. Referring to Fig. 1, which shows the unit IT in section, the shaft 8, which is journaled in a housing H, has a slidable clutch member l8 slidable thereon and secured against rotation relative thereto by a key IS. The clutch member I8 is provided with conical portions at opposite ends thereof and the right hand portion engages at its right hand end of movement with a conical brake member 20' forming a part of the housing IT, to hold the shaft 8 and accordingly the spindles in the tool heads 6 against rotation. The clutch member Ill when moved to the left out of engagement with the brake 20', engages a conical member 2| which is secured to the end of the shaft l4, above noted, so that when the member H3 is moved to the left hand end of its movement, said member l8 engages the member 2| to procure rotation of the shaft 8 in unison with the shaft H. A circumferential groove 22' in the clutch member I8 is engaged by an actuating member 23' through whichthe clutch member l8 may be shifted.

The work to be operated upon is carried by a fixture or bracket 20 of any desired type mount: ed on the carriage, the fixture shown in Figs. 1, 2 and 3 being of the reversible orindexing type comprising a rotatable member 2| supported by trunnions 22. The rotatable member is adapted to clamp workpieces a indicated in dotted lines, in a position to be operated upon by the boring tools, by means ofclamping bars 23 held in clamping position by wing nuts 24, the surface of the workpiecestmbe bored being located by a-manually operated plug 25. Clamping bars 23 are provided on opposite sid es of the rotatable member, so that the workpieces carried on the under side of the rotatable member may be operated upon by thetool while thefinished work-'- pieces on the upper-side are being removed and unfinished workpieces substituted therefor. The

rotatable member is swung through after the workpieces on the .under side Fig. l, have been completed toswing the unfinished workpieces beas the carriage in the opposite direction.

In this manner, one group of workpieces may be loaded while the others are being bored, the rotatable member being held in desired position by an arm 2| which engages locating surfaces on opposite sides of the bracket as the member is swung through'lSO".

The table or carriage is reciprocated on the ways by fluid under pressure, reciprocations of the carriage being procured by the admission of fluid under pressure alternately to opposite ends of a cylinder 26 supported by the base. Said cylinder has a piston 21 slidable therein, and a piston rod 28 extending outwardly thereof, the outer end of the piston rod being connected to a depending bracket 30 on the carriage. The movements of the carriage are controlled by spaced reversing dogs 3| and 32 which are mounted on the carriage which alternately engage and actuate a reversing lever 33, thereby, to direct the fluid under pressure alternately to opposite ends of the cylinder and cause the carriage to reciprocate. The lower end of the reversing lever' en" gages a pin 34, Fig. 4, carried by a crank 35, the latter being mounted on the forward end of a pilot valve 36, so that rocking movement of the reversing lever, in response to engagement of said lever with the dogs 3| and 32 rocks said'valve member, thereby controling the direction of flow of fluid to the cylinder. 1 The hydraulic system for actuating the carriage is shown most clearly in Figs. 4, '7 and 12; Fluid under pressure-is admitted through a pipe 31 from any suitable source such as a fluideprese sure pump to a channel 38 in the rearward end of a throttle valve 40 rotatably mounted in a longitudinal .bore 4| in the casting 42 in which the valve mechanisms are mounted. The throttle valve is recessed at 43 to intersect the channel 38 so that the amount of fluid flowing from the recess into a port 44 provided in the bore 4| adjacent the valve recess may be varied in response to turning movement of the valve 40 as will be apparent from Fig. 7. The port 44 is connected by a channel 45 (pipe 45, Fig. 12) in the casting 42 to a central inlet port 46 in the casing or sleeve 41 for the reversing or main valve 48, said casing being received in a transverse bore 50 in the casting 42. The casing 41 is provided with spaced outlet ports 5| and 52 adjacent opposite pipes 62 and 63 to opposite ends of the cylinder 26. The channels 51 and 58 are represented as separate elements in Fig. 12 in order to make the arrangement of the parts more clear, said channels being identified in Fig. 12 as 51' and- 58-.

the channels 51 and 58 as shown in Fig. '7, said channels are represented, in the diagrammatic showing of Fig. 12, as being connected by pipes 51" and 58" respectfully to said ports 5| and 52.

to avoid confusion, is identified as 45'.

The main valve 48 comprises spaced cylindrical portions 54, 65, 66 and 61 connected by corresspending cylindrical portions 68, I0 and II or Although the ports 5| and 52 open directly into 4 Channel 45 is indicated in Fig. 12 by a pipqwhich,

smaller diameter and 'end'portions l2 and lf'als'o main valve has a central opening 16 longitudinallytherethrough, the ends of which are substantially closed by plugs 11 and 18, the latter having small channels or bleed ports and 8| respectively therethrough. Ports 82, 83 and 84 are provided in the righthand end cylindrical portion 12, the central cylindrical portion 10 and the left hand end cylindrical portion 13, respectively, to permit fluid under pressure to enter and escape from the central opening 16 so that fluid may flow from the inlet port 46 into the central opening 16 through port 83 and out through either of the bleed ports 80 or 8| in the plugs 11 or 18 or out the ports 82 and 84, as will hereinafter appear. Caps 85 and 86 are arranged to cover the ends of the bore 50 to retain the casing 41 therein, said caps having bores 91 and 88 respectivelytherein, which are of a suitable diameter slidably to receive the enlarged ends 14 r and 15 of the main valve 48. Channels 90 and 9| in the caps connect the bores 81 and 88 to channels 92 and 93 in the casting 42, and the latter channels 92 and 93 intersect the longitudinal bore 94 in the casting 42in which the pilot valve 36 is mounted. The channels 92 and 93 are represented by pipes 92 and 93' in Fig. 12, the channels 90 and 9| being shown in this figure as integral with casting 42.

The pilot valve is arranged to provide fluid connection alternately from said channels 92 and 93 to the exhaust opening 56. As best shown in Figs. 4 and 7, the pilot valve 36 is provided with a longitudinal channel 96 throughout a portion of its length, said channel opening at the rearward end of the valve into the bore 94 which receives said valve, said bore being connected by a channel 95, indicated by an open pipe in Fig. 12, in casting 42 to the exhaust 56. The valve is also provided with a semicircular recess 91 inter- ,secting the longitudinal channel, said recess being located adjacent the intersection of channels 92 and 93 with the bore 94. From a consideration of Fig. 7, it will be apparent that movement of the pilot valve 36 in response to rocking movement of the reversing lever 33, as above pointed out, alternately connects one of the channels 92 and 93 to the exhaust opening 56 at the same time closing the opposite channel.

Fluid entering through the inlet port 46 passes into the central opening 16, Fig. 7, of the main valve and out through the small channels 80 and 8| in the plugs into channels 90 and 9|. Since one of the channels 92 or 93 is closed to the exhaust, fluid pressure is builtup in the channel and bore at the closed end, thereby urging the main valve 48 into its opposite end position, the

fluid escaping from the bore in the other cap through the pilot valve and out the exhaust opening to permit movement of the main valve. Similarly, when the pilot valve is reversed, the main valve is urged in the opposite direction.

With the pilot and main valves in the position shown in Figs. 7 and 12, fluid from the pump flows through the throttle valve 40, and the channel 45 to the inlet port 46 in the casing 41, from which port the fluid passes through the port 83 into the opening 16 within the main valve passing through the port 84 into theport 52 and thence to the channel 58. The movement of the fluid under pressure in the casing 41 is limited by. the cylindrical portions 64, 65, 66, 61, which retain the fluid outside the main valve between the adjacent cylindrical portions. From the carriage is reversed, the carriage being channel 58 the fluid enters the left hand end of the cylinder 26 through the pipe 63, thereby urging the piston 21 and accordingly the carriage to the right. Fluid from the central opening 16 in the main valve also passes through the bleed port 8|, building up pressure in the channel 9| and bore 88, thereby maintaining the valve in the right hand position shown. As the carriage reaches the right hand end of its stroke, the reversing dog 32 engages and rocks the reversing lever, thereby rotating the pilot valve counterclockwise to permit fluid to exhaust through the channel 93 from the bore 88 at the left hand end of the main valve and to close the channel 92 connecting to the right hand end of the main valve, whereby pressure is built up on the right hand end of the main valve, urging said valve to the left. This movement of the main valve cuts off the flow of fluid under pressure from the inlet port 46 to port 52 and provides fluid connection between the inlet port 46 and the port 5| to the-channel 51 connecting said port to the pipe 62, and thence to the right hand end of the cylinder 26 so that the direction of movement f the ged to the left until the reversing dog 3| engages and rocks the reversing lever at left hand end of stroke, thereby returning the pilot valve 36 to the original position, so that the movement of the carriage is again reversed and the carriage is urged to the right.

As the fluid under pressure is admitted to the left hand end of the cylinder 26, the main valve being in the position shown, fluid is exhausted from the right hand and of said cylinder through the channel 51 and the port 5| into the space between the spaced cylindrical portions 64 and 65, through the exhaust port 53 into the channel 55 and thence to the exhaust opening 56. When the main valve 48 is shifted to the left to cause the table to move toward the left, fluid exhausting from the left hand end of the cylinder flows from the channel 58 through the port 52 into the space between the cylindrical portions 66 and 61, through the exhaust port 54 into the channel 55 and out through the exhaust opening 56.

The table is actuated at maximum speed during the inoperative movement of said table when the boring tools are out of engagement with the workpieces, ,said table being slowed down during the operative boring movement when the tool on either bridge is in engagement with the workpiece. As shown in Figs. -1 and 6, speed control dogs 98 and 99 are mounted on the under side of the carriage for engagement with upstanding latches I00, and IN. Arms I02 and I03, Fig. '6, are rigidly mounted on shafts I04 and I05 respectively, the latter being rotatably mounted in the base I, and support the latches atthe ends remote from the shafts I04 and I05. The latches I00 and |0| are pivotally mounted on pins I06 and I01 in the end of the arms, said latches being held positively against movement from upstanding position in one direction by engagement of a surface of each latch with a portion of the corresponding arm. The rocking movement of the latches in the opposite direction is limited in extent, by plungers I06 and I09 mounted in recesses H0 and III respectively, in the arms I02 H6 and I I1 of the speed control valves 60 and 6|- As the carriage is actuated to the left by fluid passing valve 60 to the right hand end of cylinder 26, the speed control dog 96 engages the upper end of the latch I00 urging the latch downwardly, thereby rotating the arm I02 and accordingly the arm II4 counterclockwise and urging the upstanding end II6 of' the speed reducing valve 60 downwardly to diminish the fluid flow to the cylinder 26, thereby reducing the rate of movement of the table during the movement of the workpiece past the tool on the left hand bridge. The dog 98 is located to engage the latch I00 immediately prior to engagement of the tool with the workpiece and the upper end of the latch and the corners of the dog are bevelled to permit said dog to ride over the end of the latch in order to actuate said latch. The dog 88 is somewhat longer than the length of the workpiece to be operated upon so that the latch I06 is depressed just prior to the engagement of the boring tool with the workpiece and is released directly as the boring tool passes beyond the workpiece. It is not necessary that the slow-down valve be released prior to reversal of the carriage movement since the carriage is positively actuated by fluid under pressure until the pilot valve 36 has been shifted from one extreme position to the other.

It will be noted that the table is slowed by the latch I00 in only one direction of table travel, that is, as the table is reversed after the tool has passed over the workpiece, the latch I00, which is depressed during the boring operation and is released at the end of the stroke, is rotated against the pressure of the spring II2 sov that as the carriage moves to the right, the arm I02 is not rotated and accordingly the speed reducing valve is not depressed. Similarly, as the carriage continues to move to'the right, the dog 89 de presses the latch IOI, rotating the arm I03 and I I5 clockwise and depressing the upstanding end Q N1 of the speed reducing valve 6I to diminish the rate of travel of the table as the workpiece passes the boring tool on the right hand bridge. The dog 99, similar to the dog 98, reduces the speed of the carriage during the right hand move- I ment only thereof, the latch IOI rocking against the pressure of the spring H3 as the carriage subsequently moves to the left after having been reversed so that the speed reducing valve Si is not depressed during the left hand movement of the carriage.

The speed reducing or slow-down valves 60 and 6! actuated by the dogs 98 and 99 are located 'in the forward ends of the channels 51 and 58,

substantially vertical bores being provided in the casting 42 for the reception of said valves, the valve 60 being shown in Fig. 4 andthe valve 6| being shown in Fig. 11. Since the valves are identical in construction, the description of one will suflice for both. Referring particularly to Fig. 11, which shows the speed control valve 6| for the left-hand end of the cylinder 26, the valve 6I is slidably received in the vertical bore 0 in the casting 42, the lower end of the bore intersecting the forward end of the channel 58. A similar bore II9, Fig. 4, which intersects channel 51, receives the valve 60 for the fluid passing to the right hand end of the cylinder 26. A cap I is provided for the upper end of the bore II8 beyond which the upstanding end II1 of the valve stem I2I extends and the lower end of the valve stem is enlarged at I22 for engagement with Q the under surface of the cap to limit the upward movement of said stem and to hold the end I I1 in position for engagement with the arm I I5. A pin I23 extends through the lower end of the valve 5 stem I2I and engages in openings I24 in the valve,

the openings being a. larger diameter than the pin to permit movement of the stem relative to the valve, whereby the movement of the valve stem in response to the rocking of arm 5 may be greater than the resultant valve movement. Directly beneath the enlarged portion I22 is a flange I25, the under side of which is engaged by a coil spring I26 surrounding the stem. The lower end of the spring engaging in a recess I21 formed in the upper end of the valve, said spring I26 normally holding the pin I23 against the upper edge of the openings.

. The valve is provided substantially centrally thereof with a transverse bore I28, one end of which receives the inner end of an elongated rod I30, which is tapered at I3I, in order to regulate and to limit the movement of the valve within the bore. The lower end of the valve is reduced in diameter as indicated at I32 to engage within the bore I33 of a sleeve I34 received within the lower end of the bore II8, said sleeve having a port I35 in the side coinciding with the opening to the channel 58, and the top surface of the of the valve normally maintains the valve in this position, said spring engaging the upper surface of said sleeve and the shoulder I38 on said valve at lower and upper ends respectively. The spring I31 is lighter than the spring I26 so that as the valve stem I2I is urged downwardly, the valve 6I moves downwardly therewith, the spring I31 being compressed until the upper edge of the transverse bore I28 engages the inner end of rod I36 after which said valve is held by said rod against further d wnward movement during the continued downward movement of said valve stem, the pin I23 which connects said valve to said valve stem moving relative to the openings I26 by compression of spring I26. A central channel I40 is formed longitudinally through the valve in order to permit fluid to pass to and from the upper end of the bore H8 in order to permit unrestricted movement of the valve. As the valve stem I2I is urged downwardly in response to the speed control dog 69, the valve 6| being urged downwardly therewith, the groove I36 is partially closed, to limit the amount of fluid flowing from the'channel 58 into the port I39 which connects to the pipe 63, thereby reducing the speed of the table. The flow of fluid through the slow-down valve is obviously reduced in proportion to the amount of downward movement of said valve and the speed reduction is accordingly controlled by the position of the lower edges of the space controlled dogs 96 and 89.

The speed reducing valve 60 is similarly cone structed and mounted in the vertical bore I I9, the lower end of said bore intersecting the forward end of the channel 51 and the outlet for said valve 60 being indicated at 62 in Fig. 4. The sliding movement of valve 60 is controlled by a rod I, Fig. 4, similar, to rod I30, having a tapered end corresponding to the tapered end of said rod I30, said 'end engaging in the transverse bore I42 of valve 60. The forward end of the rods I30 and HI are threaded as indicated at I43, Fig. 4, on the rod I4I, rotation of the rods procuring in or out movement in the casting 42 to limit the movement of said valves and accordingly the extent to which the grooves on said valves are closed. The cover plate I44 n the front of the casting 42 is recessed as indicated at I45 to receive a. coil spring I46 which surrounds the rod I4I, the forward end of said coil spring engaging the inner surface of a knob I41 by which said rod is rotated, another recess I48 being provided in the front of the casting to receive a small portion of the knob I41. The cover plate I44 is. similarly recessed and provided with a spring which is urged against the inner surface of a knob I49 for the rod I30, the knobs being indicated on the front of the machine in Fig. 1.

The rotation of the boring heads on the bridges is controlled by valves I50 and II which are received in. longitudinal bores I52 and I53 in the casting 42 directly beneath and parallel to the channels 51 and 58. As best shown in Fig. 8, the valves are provided respectively with longitudinal channels I54 and I55 extending from the inner or rearward end of the valves, said channels being closed at their inner ends by plugs I56and I51. Transverse horizontal channels I58 and I60 in the valve I50 and similar transverse horizontal channels I6I and I62 in the valve I5I intersect the longitudinal channels I54 and I55 respectively adjacent theirforward ends; and vertical channels I 63 and I64, extending downwardly through the valves, also intersect the longitudinal channels I54 and I55 respectively adjacent their forward ends, said vertical channels I63 and I64 being indicated as horizontal channels identified as I63 and I64 respectively in Fig. 12 for the sake of clarity. Other transverse channels I65, I66 and I61 intersect the longitudinal channel I54 and similar transverse channels I68, I and HI intersect the channel I55 adjacent the rearward ends thereof. Channels I61 and HI extend completely through the valve and intersect with'downwardly opening channels I12 and I13respectively. Short longitudinal channels I14 and I 15, having downwardly extending vertical channels I16-and I 11 intersecting therewith, are open into the bores I52 and I53 beyond the rearward end of the valves. Vertical channels I 18 and I80 extend completely through the valves I 50 and I 5| substantially midway between the downwardly extending channels I12 and I16 in valve I50 and I13 and I11-in valve I5I respectively. The valves are held against rotation by longitudinal recesses I BI and I82 which are engaged by pins I83 and I84 extending transversely in the casting 42, said pins being held in engagement with the recess by springs I85 and I86, the latter held inplace by plugs posite heads are rotated during the operative stroke of the' carriage, that is, the right hand boring head is ---rotated during the right hand movement of the carriage and the left hand boring head is rotatedduring the left hand movement of the table. In order to stop the rotation of the boring heads, the valves I50 and I5I are pushed rearwardly until the inner surface of knobs I92 and I93 on the forward ends of said valves engage the surface of the cover plate member I 44, as will be apparent in Fig. 8. If it is desired to rotate the boring heads continuously, the valves may be drawn forwardly until shoulders I94 and I95 on the valves I50 and I5I engage the inner surface of the said plate I44 at which time the clutch and brake mechanisms controlled by said valves operate entirely independently of the reciprocations of the table.

When the valves I50 and I5I are in the central position shown, the boring heads are started and stopped in response to the reversal of the table movements at either end, the left hand boring head being started at the .right hand end of movement of the table and being stopped at the left hand end of movement directly after the workpiece has passed the boring tool during the left hand movement, and similarly the right hand boring head being started at the left hand end of movement of the table and stopped at the right hand end of movement of the table directly after the workpiece-has passed boring tool on the right and bridge. The starting and stopping of the boring heads are controlled by pistons I96 and I91 slidably mounted in transverse bores I 98 and I99 in casings 200 and I mounted on opposite sides of the casting 42, transverse bores 202 and 203 being provided in said casting, as shown in Fig. '1, for the reception of said casings. The pistons are provided with elongated piston rods 204 and 205 extending beyond said casings. and said piston rods are positively connected respectively to the clutch and brake mechanisms l1 and I8 by engagement of said piston rods with the actuating members 23' of the clutch and brake units I1 and I8 respectively. The arrangement is such that the clutches are disengaged and the brakes engaged when the pistons I96 and I91 are in extreme right and left hand positions, respectively.

Referring particularly to Fig. 7, fluid connections are provided between the inner ends of the bores I96 and I99 which receive the pistons I96 and I91 and the corresponding channels 51 and 58 respectively, through vertical channels 206 and 201 formed in the casting 42 and intersecting channels 51 and 58, through the vertical chan-' nels I18 and I80 in the valves I50 and I5I and short channels 208 and 209 in line with the channels 206 and 201, the channels 208 and 209 opening into the inner ends of bores I98 and I99.

The channels 206, 201, 208 and 209 are indicated by pipes 205', 201', 208', and 209' respectively in Fig. 12.

Fluid connection is provided from the outer ends of the bores I98 and I99 for the pistons I96 and I91 to the opposite channels 58 and 51 re spectively through channels 2I4 and 2I5 in the casings 200 and 20I, the channels 2I6 and 2I1 in the casting 42 in line with said channels 2J4 and 2I5, into the transverse channels I66 and I10 respectively in the valves I50 and I5I, intowhich the channels 2 I4 and 2 I 5 open, and thence to the longitudinal channels I 54 and I55. The channels 2I4 and 2I6 are indicated in Fig. 12 by a,

. pipe 2I8, and the channels2l5 and 2" are indicated by a pipe 220. Referring to Fig. 10, fluid connection is provided from the longitudinal channel I54 in the valve I50 to .the left hand channel 58 to complete the connection from the 'outer end of the casing for the right hand piston to the left hand channel 58. A transverse bore or channel 22! is provided in the casting 42 midway between the channels 51 and 58 and the bores I52 and I53 for the valves I and I5I. A vertical channel 222 extending from the channel 58 intersects the channel 22I, and another vertical channel 223, which intersects the channel 22I enters into the bore I52 which receives valve I50 and connects with the vertical channel I63 in said valve. Since the channel ltd intersects the longitudinal channel I54, fluid connection is thus provided fromchannel 58 through valve I50 to the outer end of casing 200.

Similarly, the longitudinal channel in the valve I is connected to the channel 51 in the casing. Referring to Fig. 9, the casting 42 is provided with a transverse bore or channel 224 parallel to the channel 22L an intersecting vertical channel 225, the upper end of which opens into the channel 51 and the lower end of which intersects the channel 224, and a vertical channel 225, the latter intersecting the channel 224 and opening into the bore for the valve I55 at a point which coincides with the vertical channel I64 in said valve, said vertical channel I84 intersecting the longitudinal channel I55 of the valve I50. Thus fluid connection is provided from the outer or left hand end of easing 20I through channel I 55 to the channel 51. Fluid flows through channels 222, 22I, and 223 in that order, and said channels are indicated in Fig. 12 by the single pipe 221 between channel 58 and valve I50. Similarly the channels 225, 224 and 226, in that orderare indicated in Fig. 12 by a pipe 228 between channel 51 and valve I5I.

It will thus be seen that with the main valve 48 in the position shown in Figs. 7 and 12, so that fluid under-pressure is admitted to the channel 58, the channel 51 being connected through said valve to the exhaust outlet 56, fluid under pressure passes from the channel 58 through the pipes 201' and 209 into the inner end of the casing 20I urging the piston I91 to the left, thereby disengaging the clutch and energizing the brake in the left hand clutch and brake unit I8, the fluid from the right hand end of the easing 20I exhausting through the pipe 220 into'the longitudinal channel I55 and through the pipe 228 to the channel 51 which is connected'to the exhaust, as above pointed out. At the same time fluid under pressure from the channel 58 passes.

through the connection 221 into the longitudinal channel I54 and through the pipe 2I8 to the outer or right hand end of the casing 200, thereby urging the piston I96 to the left, bringing the clutch into engagement and releasing the brake in the clutch and brake unit I1. The fluid from the left hand or inner end of the casing. 200 exhausts through the pipes 2I2 and 2I0 through channel I18 into the channel 51 which is connected to the exhaust. It will be apparent that, as the movement of the carriage is reversed at the left hand end of the stroke, the boring tools on the left hand bridge are brought to rest and the boring tools on the right hand bridge are set in rotation so that, as the carriage moves toward the left, the completed workpiece is drawn past the boring tools on the left hand bridge while the said boring tools are not in motion, the right hand boring tools rotating in readiness to operate on the unfinished workpiece as the carriage continues to move to the right.

Similarly at the right hand end of the car' rlage. movement, when the m valve is urged into the left hand position, thereby admitting fluid under pressure to the channel 51 and connecting the channel 58 through said valve to the exhaust outlet 56, the pistons I96 and I51 are both urged from the position shown in Fig. 12 to the right, thereby stopping the rotation oi the tools on the right hand bridge and setting the tools in the left hand bridge in motion. The pis ton I 83 is moved to the right by fluid under pres sure which flows from the channel 51 through the pipes 205' and 205 into the left hand end of the casing 200, fluid from the right hand end of the casing exhausting through connections 2,

longitudinal channel ltd and the pipe 281 to the channel 58, which is now connected to the exhaust. The piston It? is urged to the right by fluid under pressure from the channel 51 through the pipe 228, the longitudinal channel I and the pipe 220 into the left hand end of the casing 202, fluid from the right hand end exhausting through the pipes 288 and 201' into the channel 58 which is now connected to the exhaust' In order to stop the rotation of the boring heads on either brldge,-the corresponding valve M0 or I5I is pushed inwardly until the inner surface of knob I92 or I03 on the forward ends of the valves engages the surfaces of the plate member I44. With the valves inthis inward position fluid under pressure is admitted to both ends of the casings 200 and 20I regardless oi the position of the carriage. By reason of the difference in area of the inner and outer ends of the pistons I98and I 91, the piston rods being and 12', the throttle valve 40 is provided with a longitudinal channel 230 therein extending forwardly' from the recess 38, the forward end of the channel intersecting a transverse channel 23I, the latter extending outwardly to a circumferential groove 232 in the valve 40. A horizontal channel 233, represented by a pipe 238' in Fig. 12, is provided in the casting and extends from the bore 4I adjacent the groove 232 to the bore I52, the opening of said channel into the bore I52 being closed when the valve is in automatic or central position, but with the valve in inward position said opening coincides with the short transverse channel I58, thereby admitting fluid under pressure from thefluid inlet 31 into the longitudinal channel I54 and outwardlythrough the short transverse channel I61 which in inward position coincides with the opening to thereonnection 2I8 to the casing 200. A corresponding channel 234 represented by a pipe 234' in Fig. 12, is provided in the casting 42 extending from the bore 4I adjacent the groove in the valve '40 to the bore I53 for the valve I5I, the opening in the bore being closed when the valve is in central position, but when the valve is in inward position, said opening coincides withthe trans, verse channel I6I which intersects the longi--- tudinal channel I55, thereby admitting fluid under pressure from the fluid inlet 31 through the longitudinal channel I55 to the pipe 220, the transverse channel I1I in the val llil coinciding with the opening to said connection fromthe valve, the fluid flowing through said connection to the left hand end of the casing 20I.

Fluid under pressure is admitted to the inner end of the casing 200 from the longitudinal channel I54 through the channel I 61 to the vertical channel I12, which in the inward position of the valve coincides with the opening to the pipe 208' to the casing 200. In a similar manner, fluid under pressure enters the inner or right hand end of the casing 2! from the channel I55 through the channel "I and the vertical channel I13 into the pipe 209f which connects to said casing. It will thus be seen that, with the valves I50 and I5I in inward position, fluid under pressure isadmitted to both ends of casings 200 and "I, so that the pistons I91 and I98 are urged toextreme right and left hand positions respectively, thereby stopping the rotation of the boring heads independently of the movement of the carriage, said heads remaining stopped until the valves I50 and I5I are again moved.

When the valves I50 and I5I are in extreme forward or outer position, the boring heads on both bridges rotate continuously independently of the movement of the carriage.

Referring again to Figs. 8 and 12, fluid under pressure from the fluid inlet 31 flows through channels 230 and 23I into the channel I50 of valve I50, since with valve I50 in forward position, channel I coincides with the opening to the channel 233, the fluid flowing from said channel I50 through the longitudinal channel I54 and the transverse "channel I85 into the pipe 2I8 to the right hand end of the casing 200, the' channel I now coinciding with the opening to the pipe 2I8. At the same time, fluid from the left hand end of casing 200 exhausts through the pipe 208' into the downwardly extending channel I18, which coincides with the opening to said pipe, into the longitudinal channel I14 and thence to the bore I52 for the valve I50 at the rearward end of the valve. An exhaust connection 235, Fig. 8, is provided at the rear end of the bore I52 through which the fluid may exhaust from the channel I14, whereby fluid from the left hand end of the casing 200 may exhaust. Similarly, with the valve I5I in forward position,fluid under pressure flows from the fluid inlet 31 through the channel 234 into the transverse bore I82, which now coincides with the opening of the channel 234, and thence into the longitudinal channel I55 and through the transverse channel I68 to the left hand end of the casing 20I through the pipe 220, said channel I58 now coinciding with the opening to pipe 220. Fluid from the right hand end of the casing 20I exhausts through the pipe 208' into the vertical channel I11, through the longitudinal channel I15 and into the bore I53 of the valve I5I at the rearward end of the valve. An exhaust connection 236, Fig. 8, is provided in the rearward end of the bore I53 for the exhaust fluid from the channel I15, so that fluid from theright hand end of the casing 20I may exhaust. It will thus be seen that with the valves I50 and I5I in forward position, the-pistons are urged into left and right hand positions respectively in which positions both of the clutch units I1 and I8are engaged and the brakes of the same units are disengaged so that the boring heads on both ends of the machine rotate continuously regardless of the reciprocating movements of the carriage.

It will be noted that either valve I50 or I5I may be placed in any of its three positions independently-of the position of the other valve. That is, either valve may be placed in the inward position in which the boring head for'the corresponding bridge does not rotate, in automatic position in which the boring head for the .corresponding bridge rotates in response to movements of the carriage, or in forward position in which the boring head for the corresponding bridge rota'tes continuously, regardless of the position of the other valve.

The .carriage may be positively brought to rest in anydesired position of travel to stop the operation of the machine, the mechanism by which the table is brought to rest being under the control of the operator. Referring to Fig. 1, stop dogs 231 and 238 are adjustably mounted on the under side of the carriage and are adapted at extreme left or right hand movements of the carriage to engage respectively with studs 240 and 24I rigidly mounted on the base of the machine. The upper end of the reversing lever 33, which is engaged by the reversing lugs 3| and 32, is provided with an eccentrically mounted striking member 242, said member being mounted on the rearward end of a horizontal shaft 243 pivotally mounted in the upper end of the reversing lever, the forward end of the shaft carrying an upstanding lever 244 secured against rotation on said shaft. Rocking movement of the lever swings the striking member 242, thereby moving the striking surface of said member toward or away from the reversing dogs. A spring 245 is mounted in a recess 246 surrounding the shaft 243,- said spring engaging a portion of the upstanding lever 244 to hold 'the lever and thus the striking member in desired position.

Figs. 13 and 14 are fragmentary views of the mechanism for stopping the movement of the carriage, Fig. 13 showing the reversing dog 3| and the stop dog 231 at the right hand end of the carriage and the relative position of said dogs to the reversing lever when the carriage is in substantially mid position, and Fig. 14 showing the same dogs whenthe carriage has been brought to a stop at the end of the left hand.

movement. When the lever 244 is rotated from the vertical position of Fig. 13 to the diagonal position shown in Fig. 14, the surface of the striking member is moved a substantial distance away from the reversing dog 31 so that as the carriage moves toward the left, the reversing dog engages the striking member and swings the reversing lever into vertical position at which time the stud 240 engages the left hand edge of the stop dog 231 so that the reversing lever is actuated only into vertical position and thus rotates the reversing valve to close both channels 92 and 93, thereby to prevent movement of the table in either direction. The fluid pressure, acting on the right hand end of the piston which actuates the table, serves to hold the stop dog in engagement with the stud. When the operator wishes to set the machine again in'operation, the lever 244 is rotated into a vertical position so that the surface of the striking member is moved to the right with the result that the upper end of the reversing lever is swung to the left, the reversing dog being in engagement with the striking surface, so that the channel 85 is again open to'the exhaust and the table moves to the right. In a similar manner when the lever 244 is swung into a diagonal position to the right of the vertical position, the carriage is brought to rest at the right hand end of movement by the engagement ofthe stop dog 238 with the stud 24I just as the reversing dog 32 engages the striking surface-and moves the reversing lever into vertical position. Subsequent return of the lever to'vertical position causes the reversing lever to swing to the right rotating the pilot valve to permit fluid to exhaust through travels in the opposite direction. However, when the carriage is to be brought to rest, the operator swings the lever 2, thereby spacing the striking member'from the reversing dog so that as the reversing dog engages and actuates the reversing lever, the corresponding stop dog engages the corresponding stud and prevents the carriage from traveling far' enough to swing said reversing lever beyond the vertical position. It will be notedthat the machine may be brought to rest in any desired position by suitable adjustment of the stop dogs relative to the studs so that if the boring head on only one bridge is to be used, the carriage may be brought to rest after the 'workpiecehas been withdrawn from engagement with the operative boring head without bringing the workpiece into operative engagement with the inoperative boring head on the other bridge. The speed reducing dogs are preferably a iusted so that when the stud engages thest'op dog to bring the carriage to rest,

said carriage will be moving at a reduced speed,

thereby preventing excessive shock on the machine. With the' parts in the position shown, when the carriageis brought to restat either end of the stroke *.the location of the speed reducing valve is such that the table is traveling I ati, reduced speed. I 7

By the valve construction shown the carriage has a short dwell at each end of the stroke before the beginning of the movement of the carriage in the opposite direction. As soon asthe reversing lever is shifted by either of the reversing dogs, the corresponding stop dogengages the cooperating stud on the base and prevents further movement of the carriage until the main valve 48 is shifted. It will be apparent that when the pilot valve 36 is shifted, as a result of the shifting movement of the reversing lever, the flow of fluid through either of the conduits 82' or 93', Fig. 12, is cut off, but the main valve 48 is'not shifted until the pressure at the end of the valve has been built up by passage of fluid through the bleed port til or 88 to a sumcient extent to shift the valve. Obviously the length of time occupied by the dwell of the carriage is controlled by the size of the bleed ports and the dwell occurs subsequent to the shifting of the pilot valve 36 and between the shifting of this valve and the shifting of the main valve 48;.

Since the forward end of the throttle valve 49 is provided with a crank 24], Fig. 4, by which said valve may be opened, or closed as desired, the hydraulic system is completely controlled from the front of the machine;- Movement of crank .35. either manually or. in response to the reversing dogs rotates the pilot valve to direct fluid alternately to opposite ends of the cylinder which actuates the carriage, and movement of crank 24'! varles. the maximum speed of the carriage by opening or closing the throttle valve 40.

The reduction in speed, which is controlled by the speed reducing valves, is determined by ad- .iustment of knobs I41 and H9-,-thereby' con; trolling the movement of said valves in response to movement of the'carriage. The movements of the boring heads are also controlled from ,the front of the machine by knobs I92 and I93, said heads either rotating *continuously, or being actuated in responseto movement of the carriage, or remaining at rest independently of the carriage movement, depending on whether the valves are in full outward position, central or mid position, or full inward position.

1. In a machine of theclass described, a tool member and a work-supporting member, a reciprocating carriage supporting one of said members to procure a relative movement between said members, means to actuate said carriage comprising a fluid pressure source, a cylinder and. piston, one of which is connected-to said carrriage, and reversing means alternately to admit fluid under pressure from said source to opposite ends of the cylinder, and means to control the operation ,of said tool member, said means comprising a piston. and a cylin and valve means normallyadmitting fluid der pressure alternately to opposite ends of said cylinder in response to said reversing means, said valve means being arranged for manual movement to procure continuous operation of said tool independently of said reversing mem- .ber,.and for other manual movement to maintain said tool member at rest independently of said reversing means.

'2. In a machine of the class described, a rotary tool member, a carriage actuated by fluid under pressure and arranged for,reciprpcatory movement, means to control the rotation of the tool member comprising a piston and cylinder, said piston when adjacent one end of said cylf inder procuring rotation of said tool member and when adjacent the other end of said cylinder maintaining said tool member at rest, means alternately to direct fluid under pressure to opposite ends of said cylinder in response to movement of said carriage whereby said tool rotates during the movement of the carriage in one direction and remains at rest during the movement of the carriage in. theopposite direction, and manually controlled means to admit fluid under pressure independently of the carriage movement to said cylinder whereby the tool member remains at rest, said manually con trolled means being further operable to admit fluid to the oppcmite end of said cylinder where;

pendently of the carriage .movement.

3. In a machine of the class ,described, a base, a reciprocatory table on saidbase, rotary spindles on said base at-opposite ends of said table, means to actuate said-table,- comprising a pressure source, a'cylinder and-piston,- one of which is connected to said table, and reversing means alternately to admit fluidunder pressure from said source to "opposite ends of the cylinder by the tool member rotates continuously indefthrough connections between "said reversing means and said cylinder, a throttle valve in each' of said connections and means a; said table for actuating one of said throttle valves in one'direction only of the movement of the'- table to ,diminish the rate oftravel during a portion oi the movementof the table fn the one direction and other means on said table to actuate the otherthrottle valve in response to movement of said table in the opposite direction to diminish adjacent opposite ends of said reciprocatory carriage, means to rotate the tool members adjacent one end of said base, and separate means to rotate the tool members at the opposite end of the base, fluid pressure means to actuate said carriage, means to control the rotation, of said tool members in response to movement of said carriage, whereby the tool members on one end of said base are started and stopped at opposite ends of the carriage movement, and the tool members on the opposite end of the base are stopped and started at opposite ends of the carriage movement with the tool members at either end of the carriage rotating only when the carriage is moving toward said tool members, and individual valve means to control the rotation of the tool members on opposite ends of the base, said valve means being arranged for manual movement to procure continuous operation of the tool members on either end of the base independently of said reciprocating carriage, and for other manual movement to maintain said tool members at rest independently of said reciprocat- -ing carriage.

5. In a machine of the class described, a tool member and a work-supporting member, a carriage on which one of said members is mounted, fluid pressure actuated means to procure reciprocation of said carriage for a relative movement between said members, reversing means including a reversing valve for controlling the admission and exhaust of fluid under pressure to and from said fluid pressure actuated means for reversing the carriage movement, a rotary spindle on which one of said members is mounted, other fluid pressure actuated means for controlling the rotation of said spindle, the admission and exhaust of fluid under pressure to and from said last means being controlled by the above-mentioned reversing valve for procuring cessation of rotation of the spindle at one end of the carriage movement, and other valve means for controlling the admission and exhaust of fluid under pressure to said last fluid pressure actuated means for rendering said means inoperative, whereby the spindle member will rotate continuously independently of the carriage movement.

6. In a machine of the class described, a tool member and a work-supporting member, a carriage on which one of said members is mounted, fluid pressure actuated means to procure reciprocation of said carriage for a relative movement between said members, reversing means including a reversing valve for controlling the admission and exhaust of fluid under pressure to and from said fluid pressure actuated means for reversing the carriage movement, a rotary spindle on which one of said members is mounted, other fluid pressure actuated means for controlling the rotation of said spindle, the admission and exhaust of fluid under pressure to and from said last means being controlled by the above-mentioned reversing valve for procuring cessation of rotation of the spindle at one end of the carriage movement, and other valve means for controlling the admission and exhaust of fluid under'pressure to carriage movements.

7. In a machine of the class described, a tool member and a work-supporting member, a carriage on which one of said members is mounted, fluid pressure actuated means to procure reciprocation of said carriage for a relative movement between said members, reversing means including a reversing valve for controlling the admission and exhaust of fluid under pressure to and from said fluid pressure actuated means for reversing the carriage movement, a rotary spindle on which one of said members is mounted, other fluid pressure actuated means for controlling the rotation of said spindle, the admission and exhaust of fluid under pressure to and from said last means being controlled by the above-mentioned reversing valve for procuring cessation of rotation of the spindle atone end of the carriage movement, and other manually controlled valve means for controlling the admission and exhaust of fluid under pressure to said last fluid pressure actuated means for rendering said means inoperative, thereby procuring selectively either continuous rotation of said spindle or no movement of said spindle independently of the carriage movement.

8. In a machine of the class described, a tool member and a work-supporting member, acarriage on which one of said members is mounted, fluid pressure actuated means to procure reciprocation of said carriage for a relative movement between said members, reversing means including a reversing valve for controlling the admission and exhaust of fluid under pressure to and from said fluid pressure actuated means for reversing the carriage movement, a rotary spindle on which one of said members is mounted, other fluid pressure actuated means for controlling the rotation of said spindle, the admission and exhaust of fluid under pressure to and from said last means being controlled by the above-mentioned reversing valve for procuring cessation oi. rotation of the spindle at one end of the carriage movement, and manually controlled valve means for controlling the admission and exhaust of fluid to said last fluid pressure actuated means to procure cessation of the rotation of said spindle independently of said carriage movement and in any position of said carriage.

9. In a machine of the class described, a tool member and a work-supporting member, a carriage on which one of said members is mounted, fluid pressure actuated means to procure reciprocation of said carriage for a relative movement between said members, reversing means including a reversing valve for controlling the admission and exhaust of fluid under pressure to and from said fluid pressure actuated means for reversing the carriage movement, a rotary spindle on which one of said members is mounted, otherfluid pressure actuated means for controlling the rotation of said spindle, the admission and exhaust of fluid under pressure to and from said last means being controlled by the above-mentioned reversing valve for procuring cessation of rotation of the spindle at one end of the carriage movement, and manually controlled valve means for procuring, selectively, rotation of said spindle or cessation of rotation of said spindle independently of the carriage movement and in any'position of said carriage. U

' 10. In a machine of the class described, a tool member and a work-supporting member, a carriage on which one of said members is mounted, fluid pressure actuated means ,to procure reciprocation of said carriage for a relative movement between said members, reversing means including a reversing valve for Controlling the admission and exhaust of fluid under pressure to and from said fluid pressure actuated means-for reversing the carriage movement, a rotary spindle on whichone of said members is mounted, other fluid pressure actuated means for controlling the rotation of said spindle, the admission and exhaust of fluid under pressure to and from said last means being controlled by the abovementioned reversing valve for procuring cessation of rotation of the spindle at one end of the carriage movement, and an additional valve means for controlling the rotation of the spindle so that the latter selectively may be started and stopped in response to movement of the carriage or may remain at rest independently of the carriage movement or may be continuously rotated independently of the carriage movement.

11. In a machine of the class described, a tool member and a work-supporting member, a carriage on which one of said members is mounted fluid pressure actuated means to procure reciprocation of saidcarriage for a relative movement between said members, reversing .means including a reversing valve for controlling the admission and exhaust of fluid under pressure to and from said fluid pressure actuated means for reversing the carriage movement, a rotary spindle on which one of said members is mounted, other fluid pressure actuated means for controlling the rotation of said spindle, the admission and exhaust of fluid under pressure to and-from said last means being controlled by the above-mentioned reversing valve for procuring cessation of rotation of the spindle at one end of the carriage movement, and an additional manually-controlled valve means to control the rotation of the tool member so that the latter, selectively, may rotate continuously independently of'the carriage movementor may be started and stopped in response to saidcarriage movement.

12. In a machine of the class described, a tool member and a work-supporting member, a carriage on which one of said members is mounted, fluid pressure actuated means to procure reciprocation of said carriage for a relative movement between said members, reversing means including a reversing valve for controlling the admission and exhaust of fluid under pressure to and from said fluid pressure actuated means for reversing the carriage movement, a rotary spindle on which one of said members is mount ed, other fluid pressure actuated means for controlling the rotation of said spindle, the admission and exhaust of fluid under pressure to and from said last means being controlled by the above-mentioned reversing valve for procuring cessation of rotationof the spindle at one end of the carriage movement, and an additional manually-controlled valve means to control the rotation of the spindle so that the latter may selectively remain at rest-independently of the carriage movement or may '-;be started and stopped in responseto saidcarriage movement.

13. In a machine of theclassdesribed, a base having a reciprocatorycarriage mounted there on, rotary spindles mounted onsaid base adjacent opposite ends of said reciprocatory carriage, meansto rotate the spindles adjacent one end 01' said base; bther means for rotating the f'spindles at the-:opposite end of the base, fluid pressure meags ior actuating said carriage,

means to control the rotation'ot said spindles in response to movement oi. said carriage, whereby the spindles atone end of said base are-started of the base are stopped and started at opposite ends of the carriage movement, with the spindles at either end of the carriage rotating only when the carriage is moving toward said spindles, and individual valve means for controlling the rotation of the spindles on opposite ends of the base, said valve means being arranged for manual movement to procure continuous operation of the spindles on either end of the base independently of said reciprocating carriage.

14. In a machine of the class described, a base having a reciprocatory carriage mounted thereon, rotary spindles mounted on said base adjacent opposite ends of said reciprocatory carriage, means to rotate the spindles adjacent one end of said base, other means for rotating the spindles at the opposite end of the base, fluid pressure means for actuating said carriage, means sponse to movement of said carriage, whereby the spindles at one end of said base are started and stopped atopposite ends of the carriage movement, and the spindles on the opposite end of the base are stopped and started at oppositeends of the carriage movement, with the spindles at. either end of the carriage rotating only when the carriage is moving toward said spindles, and individual valve means for controlling the rotation of the spindles on opposite ends of the base, said valve means being arranged for manual movement to maintain saidspindles at rest independently of the reciprocating carriage.

15. In a machine of the class described, a base having a reciprocatory carriage mounted thereon, rotary spindles mounted on said base adjacent opposite ends of said reciprocatory carriage, means to rotate the spindles adjacent one end of said base, other means for rotating the spindles at the opposite end of the base, fluid pressure means for actuating said carriage, means to control the rotation of said spindles in response to movement of said carriage, whereby the spindles at one end of said base are started and stopped at opposite ends of the carriage movement, and the spindles on the opposite end of the base are stopped and started at opposite ends of the carriage movement, with the spindles at either end of the carriage rotating only when the carriage-is moving toward said spindles, and individual valve means for controlling the rotation of the spindles on opposite ends of the base, said valve means being arranged for manual movement to procure continuous operation of the spindles on either end of the base independently of said reciprocating carriage, and for other" manual movement to *maintain said spindles at rest independently of said reciprocating carriage.

16. In a machine of the class described, a carriage, having a normal reciprocatory stroke, reversing means including a reversing lever for reversing the carriage movement, reversing dogs on said carriage for'shifting said lever at opposite ends of the carriage movement, thereby reversing the direction of movement of said carriage, manually positioned means on the reversing lever to render the reversing dog at one end of the stroke inoperative, said last means being manually positioned during the carriage movement, stop means to bring said carriage to rest at the end of its stroke when said manually-positioned means are inoperative, the subsequent return of SaidmanuaIIy-positioned means to operative pooperative for shifting the reversing lever to set the carriage again in operation.

17. In a machine of the class described, a tool member and a work-supporting member, a reciprocating carriage supporting one of said members to provide fora relative movement therebetween, means for actuating said carriage, including a fluid pressure source, a cylinder and piston, one of which is connected to the carriage, a reversing valve for alternately directing fluid under pressure from said source to opposite ends of the cylinder, and means including reversing dogs on the carriage and a pilot valve actuated thereby to procure a shifting movement of said reversing-valve for reversing the direction of the carriage, said means also including bleed ports to permit shifting of the reversing valve only after a predetermined time interval subsequent to the shifting of said pilot valve.

18. In a machine of the class described, a tool member and a work-supporting member, a reciprocating carriage supporting one of said members to provide for a relative movement thcrebetween, means for actuating said carriage, including a fluid pressure source, a cylinder and piston, one

of which is connected to the carriage, a reversing valve for alternately directing fluid under pressure from said source to opposite ends of the cylinder, and means for shifting said reversing valve at opposite ends of the carriage movement, said means including apilot valve, means responsive to the carriage movement for shifting the position of said pilot valve, cylinders at opposite ends of the reversing valve, the latter being in the form of a plunger slidable in said cylinders, and small bleed ports to provide a connection from the fluid pressure sourceinto the cylinders at opposite ends of said reversing valve, the pilot valve selectively cutting off the discharge of fluid from said cylinders.

19. In a machine of the class described, a tool latch to provide -for actuation of said valve by said means during the movement of the carriage in one direction-only said reversing means being operable while the slow-down valve is operative,

and cooperating means on the carriage and base to stop the carriage at a predetermined point at each end of the carriage movement after shifting of, said first valve.

20. In a machine of the class described, a base, a reciprocatory table on said'base, rotary spindles on said base at opposite ends of said table, means to actuate said table comprising a pres-- sure source, a cylinder and piston,.one of which is connected to said table, and reversing means for alternately directing fluid under pressure from said source to opposite ends of the'cylinder through connections between said reversing means and said cylinder, 9. throttle valve in each of said connections means responsive to the table movement for rendering each throttle valve operative, and means accessible from the operators position at the front of the machine for adjusting the throttling action of each of said throttle valves.

21. In a machine of the class described, a base, a reciprocatory table on. said base, rotary spindles on said base at opposite ends of said table, means for actuating said table comprising a pressure source, a cylinder and piston, one of which is connected to said table, and reversing means for alternately directing fluid under pressure from said source to opposite ends of the cylinder through connections between said reversing means and said cylinder, a throttle valve in each of said connections, means on said table for actuating one of said throttle valves in one direction only of the table movement, other means on the table for actuating the other throttle valve in response to movement of the table in the opposite direction, and means for adjusting the throt-' tling action of each of said valves independently, said last means being accessible from the opera.- tors position at the front of the machine.

22. In a machine of the class described, a tool member and a work-supporting member, a reciprocating carriage supporting one 0 said members to provide for a relative mov ent therebetween, means for actuating said carriage, including a fluid pressure motor and a reversing valve actuated in response to the carriage movement for reversing the direction of movement thereof at opposite ends of the carriage stroke, and a throttle valve for reducing the rate of travel of the carriage during a portion of its movement in one direction only, said throttle valve being actuated directly in response to the movement of the carriage am actuating member on said carriage, said throttle valve being arranged to decrease the flow of fluid therethrough in proportion to the extent of the valve movement.

23. In a machine of the class described, a tool member and a work-supporting member, a reciprocating carriage supporting one of said members to provide for a relative movement therebetween, means for actuating said carriage, including a fluid pressure motor and a'reversing valve actuated in response to the carriage movement for reversing the direction of movement thereof at opposite ends of the carriage stroke, and a throttle valve for reducing the rate of travel of the carriage during a portion of its movement in one direction only, said throttle valve being actuated directly in response to the movement of the carriage by an actuating member on said carriage, said throttle valve being arranged to decrease the flow of fluid therethrough in proportion to the extent of the valve movement, and means independent of the actuating member for adjusting the maximum closing movement of said valve for controlling the minimum rate of travel of the carriage. K *24. In a machine of the class described, a base,

a reciprocatory table on said base, rotary spindles on said base at opposite ends of said table,

means for actuating said table, comprlsing'a presspindles at each end of the table for controlling the rotationthereof, said cylinder and-piston units being connected to the reversing valve for starting and stopping of the spindle at opposite ends of the carriage movement, and manually controlled valve members for separately rendering each of said cylinder and piston units independent of the reversing valve for continuous rotation of the spindle at either end of the table.

25. In a machine or the class described, a carriage actuated by fluid under pressure, reversing means including a reversing lever for procuring a reciprocatory movement of said carriage, reversing dogs on said carriage for engagement with said reversing lever at opposite ends of the carriage stroke for actuating said lever in response to movement of said carriage, a dog engaging member carried by said reversing lever and manually controlled means on said reversing lever for shifting said dog engaging member into inoperative position to render either of the reversing dogs selectively inoperative.

26. In a machine of the class described, a carriage actuated by fluid under pressure, reversing means including a reversing lever for procuring a reciprocatory movement of said carriage, reversing-dogs on said carriage for engagement with said reversing lever at opposite ends of the carriage stroke for actuating said lever in response to movement of said carriage, a dog engaging member carried by said reversing lever, manu-' ally controlled means on said reversing lever for shifting said dog engaging member into inoperative position to render either of the reversing dogs selectively inoperative, and means to bring said carriage to rest at the end of its movement when the reversing dog is rendered inoperative.

27. In a machine of. the class described, a carriage actuated by fluid under pressure, reversing means including a reversing lever for procuring a reciprocatory movement of said carriage, reversing dogs on said carriage for engagement with said reversing lever at opposite ends of the carriage stroke for actuating said lever in response to movement of said carriage, a dog engaging member carried by said reversing lever and manually controlled means on said reversing lever tor shifting said dog engaging member into inoperative position to render either of the re- "versing dogs selectively inoperative, return of said dog engaging member to original position procuring movement of said reversing lever for a movement of the carriage in the opposite direction.

'28. In a machine of the class described, a carriage actuated by fluid under pressure, reversing means including a reversing lever for procuring a reciprocatory movement of said carriage, reversing dogs on said carriage for engagement with said reversing lever at opposite ends of. the.

29. In a boring machine, a base, a tool member and a work-supporting member, a table on which one of said members is mounted, fluid pressure means for reciprocating said table, including a cylinder and piston, one of which is connected to the table, a source of fluid under pressure, a valve for directing fluid under pressure alternately to opposite ends of. the cylinder, and means for shifting said valve, including reversing dogs on the table, a pilot valve actuated thereby, connections from said pilot valve to the main valve for shifting said valve in response to movement of said pilot valve, at least one of said connections being arranged to procurethe admission of fluid to said main valve at a slow rate whereby the table is reversed a predetermined time subsequent to the actuation of the pilot valve by the reversing dog.

WILLIAM D. SCHMID'I'.

f"-- l l w nl v I I CERTIFICATE OF CORRECTION :Patent No. 2,l7LL,OLLLL.' September 26, 1959.

of the above numbered patent requiring correction as follows: Page 1, first column, line L LL, fer "objectional r-ead objectionable; line55, after the Word "valve insert with an arrangement to cause shifting movement of the jnain valve; page 2, first column, line-9, for "spindles on" head spindles in; page 5, second column, line 27, for "and bridge" read hand'bridge; and

Henry Van Ar-sdale, (Seal) Acting Commissioner of Patents. 

